Fluid scrubbing apparatus

ABSTRACT

In one aspect there is provided a fluid treatment system for treating a contaminated fluid having a gaseous contaminant mixed or dissolved in the liquid portion thereof. The system comprises a generally enclosed and substantially airtight container defining an interior volume. The container comprises an inlet to receive the contaminated fluid, a gas outlet to discharge any gaseous contaminant and a liquid outlet to discharge any liquid that may be separated from said contaminated fluid. During operations, the container is sealed to maintain a seal between the interior volume and any outside environment, so as to prevent the escape of any liquids and gasses out of the interior volume, except as may be provided for via the inlet, the gas outlet or the liquid outlet. Also during operations, a continuous headspace is maintained between the at least one inlet and the at least one gas outlet.

CROSS REFERENCE TO RELATED APPLICATION

This application is a continuation of co-pending U.S. application Ser.No. 15/154,940, which was filed on May 13, 2016, entitled “FLUIDSCRUBBING APPARATUS” and which was non-provisional application of U.S.Provisional Patent Application Ser. No. 62/161,882 filed May 15, 2015and entitled “FLUID SCRUBBING APPARATUS”, the entireties of each ofwhich are incorporated herein by reference.

FIELD OF THE INVENTION

The field of present invention relates generally to contaminated fluidscrubbing equipment and, more particularly, to equipment and systemssuitable for scrubbing hydrogen sulfide from fluids such as sour waterand sour oil without introducing a chemical scavenger into the liquidportion of the contaminated fluid and without the need for a large scalefacility.

BACKGROUND OF THE INVENTION

The background information discussed below is presented to betterillustrate the novelty and usefulness of the present invention. Thisbackground information is not admitted prior art.

Fluids may contain contaminants that are gaseous at normal atmosphericconditions, but which are also often mixed or dissolved in the liquidportion of that fluid. Volatile Organic Compounds (VOC) are one exampleof a group of such contaminants. Another example is the contaminanthydrogen sulfide (H2S) which may be present in water, crude oil or otherhydrocarbon fluids. Hydrogen sulfide can be present naturally in wellwater and in crude oil, or it may be introduced into wastewater viaindustrial processes. Water and crude oil will be referred to as sour,if they contain substantial amounts of hydrogen sulfide.

Hydrogen sulfide is a colorless gas with the characteristic foul odor ofrotten eggs. It is also very poisonous, corrosive, flammable, andexplosive. The industry considers oil or water containing 100 parts permillion (“ppm”) (0.01%) sulfur sour oil and sour water. Although this isthe minimum level, oil wells and water can contain higher amounts. Oiland water can contain hydrogen sulfide up to 300,000 ppm (30%) at theimmediate gas/liquid interphase, the vapor space in a tank or container,and the atmosphere surrounding a spill. At higher concentrations,hydrogen sulfide is toxic and deadly. It is therefore desirable toremove or to inactivate hydrogen sulfide contaminants.

A traditional method of removing or inactivating hydrogen sulfide fromfluids such as crude oil or water is to use a chemical scavenger, forexample 1,3,5-tri-(2-hydroxyethyl)-hexahydro-s-triazine (HHTT, CASnumber 4719-04-4), usually simply referred to as triazine. This hydrogensulfide scavenger reacts with the hydrogen sulfide converting it to amore non-volatile product, which may be then subsequently removed fromthe fluid being treated or simple left in solution. However even thoughthese products are non-volatile or less toxic, it is often undesirableto leave scavenger end-products within the treated fluid (since theoverall “sulfur” content has not been reduced, but has merely beenconverted to a less toxic form). Therefore additional steps may need tobe taken to remove the scavenger end-products from the fluid, resultingin additional costs and more complex equipment.

Additionally, amine-based hydrogen sulfide scavengers are also known toform an unwanted dithiazine byproduct (particularly if the scavenger is“over-spent”). This byproduct material is also known as amorphousdithiazine, and appears to begin forming when triazine is around 60%spent. This amorphous dithiazine byproduct is exceptionally insolubleand substantial quantities can deposit throughout a fluid processingsystem. Dithiazine can form blockages in processing equipment, storagetanks, truck tanks and disposal wells. Cleanup procedures are timeconsuming and difficult. Often, the equipment has to be taken off-lineso such deposits can be manually chipped away. The industry places mucheffort and incurs great cost in the prevention and treatment ofdithiazine buildup.

Hydrogen sulfide treatment systems also often take the form of elaboratesystems employing complex components such as packing, porous media orcontact cells to increase surface areas and create tortuous fluid paths(e.g. to increase scavenger and contaminant interaction), fluid nozzlesor distributors (e.g. to attempt to evenly distribute scavenger orcontaminated fluid over the packing), demister pads (e.g. to removecontaminated liquid or scavenger droplets entrained in a vapor stream)and sparge-bars (e.g. to introduce a scavenger into the fluid). Theseelaborate systems typically are in the form of tall, upright vessels ortowers, to increase the time that fluid or scavenger trickles downwardthrough a deep layer of packing (or to increase the time that lighterfluids take to move up through a deep layer of contaminated fluid),thereby allowing the system to fully treat the contaminated fluid.

However, such upright/vertical orientation makes these systemsundesirable for use in remote locations, because the upright vessel willoften have to be transported in a horizontal orientation (e.g. to fitunderneath bridges and to meet local vehicle and traffic regulations)and then be lifted or tilted upright from a transport vehicle to beinstalled at the remote location. For example, the current CommercialVehicle Dimension and Weight Regulation under the Traffic Safety Act ofthe Province of Alberta, Canada sets the maximum width of a semi-truck,including any load, at 2.6 metres (approximately 8.53 feet) and sets theheight of the highest point of the semi-truck, including any load, at4.15 metres (approximately 16.6 feet) from the surface of the highway.The packing, porous media or contact cells may also not be suitable foruse with crude oil and/or may be expensive to use and replace.

Finally, it is known that hydrogen sulfide contaminated water can maysometimes be treated through a process of air stripping. Air strippingtypically occurs in an upright/vertical tower where the contaminatedwater is induced into the top of the tank and distributed over top of alayer of packing. The packing is designed to increase the surface areaof the air-water interface, allowing a more complete volatilization. Asthe water descends, air is introduced separately from the water, nearthe bottom of the tank. The air then rises through the packing tostripping off the hydrogen sulfide. The water collects at the bottomwith reduced hydrogen sulfide concentration and may exit through a sump.The hydrogen sulfide will then rise out of the top of the tank in agaseous state. However, this type of air stripping is normally onlysuitable for contaminated water with lower concentrations of hydrogensulfide, it may not work well with crude oil and typically results inthe packing becoming plugged or contaminated. Often the water collectedat the bottom of the tank will require further treatment to fully removethe hydrogen sulfide (e.g. with chlorination) and, if it works, ittypically requires tall, upright vessels or towers with sufficientpacking. Moreover, the use of packing complicates this system and addsto the cost, including ongoing operating material costs as packing needsto be replaced.

Therefore, what is needed is a simple, cost-effective apparatus, systemand method to efficiently scrub contaminants such as hydrogen sulfidefrom fluids without introducing a chemical scavenger into the liquidportion of the contaminated fluid, without the need for packing,suitable for transport on the highways and without requiring complex andtall systems and apparatus. Preferably, and because the liquid portionof the fluid has commercial value (e.g. the liquid crude oil), thecontaminant will be substantially removed from the liquid portion ofsuch contaminated fluid, without requiring a secondary treatment forthat liquid portion.

SUMMARY OF THE INVENTION

In an embodiment of the invention, there is provided a fluid treatmentsystem for treating a contaminated fluid having a gaseous contaminantmixed or dissolved in the liquid portion thereof. The system comprises agenerally enclosed and substantially airtight container defining aninterior volume. The container comprises an inlet to receive thecontaminated fluid, a gas outlet to discharge any gaseous contaminantand a liquid outlet to discharge any liquid that may be separated fromsaid contaminated fluid. During operations, the container is sealed tomaintain a seal between the interior volume and any outside environment,so as to prevent the escape of any liquids and gasses out of theinterior volume, except as may be provided for via the inlet, the gasoutlet or the liquid outlet. Also during operations, a continuousheadspace is maintained between the at least one inlet and the at leastone gas outlet.

In a preferred embodiment of the invention, the system furthercomprises: (i) a recycling loop fluidly connecting the liquid outlet tothe inlet, (ii) a gas scrubber to receive any gaseous contaminantsexiting the gas outlet, and (iii) a source of carrier gas premixed intothe contaminated fluid.

BRIEF DESCRIPTION OF THE DRAWINGS

Referring to the drawings, several aspects of the present invention areillustrated by way of example, and not by way of limitation, in detailin the figures, wherein:

FIG. 1 is a diagrammatic view of a first embodiment of the fluidtreatment system of the present invention;

FIG. 2 is a sectioned perspective view of an embodiment of a containersuitable for use in the fluid treatment system of the present invention;

FIG. 3 is an enlarged view of a portion of FIG. 2;

FIGS. 4, 5 and 6 are interior perspective views of one embodiment of amixer and diverter; and

FIG. 7 is a sectioned perspective view of another embodiment of acontainer suitable for use in the fluid treatment system of the presentinvention.

DEFINITION SECTION

Horizontal plane, as used herein, refers to a plane that is horizontalat a given point if it is perpendicular to the gradient of the gravityfield at that point, in other words, apparent gravity is what makes aplumb bob hang perpendicular to the plane at that point. In other wordsa horizontal plane in the plane that is perpendicular to the line thatpasses through the center of the Earth.

Vertical plane, as used herein, refers in astronomy, geography,geometry, and related sciences and contexts, to a direction passing by agiven point if it is locally aligned with the gradient of the Earth'sgravity field, i.e., with the direction of the gravitational force (perunit mass, i.e. gravitational acceleration vector) at that point.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The following description is of preferred embodiments by way of exampleonly and without limitation to the combination of features necessary forcarrying the invention into effect. Reference is to be had to theFigures in which identical reference numbers identify similarcomponents. The drawing figures are not necessarily to scale and certainfeatures are shown in schematic or diagrammatic form in the interest ofclarity and conciseness.

FIG. 1 shows a first preferred embodiment of a fluid treatment system 10for treating a contaminated fluid F having a gaseous contaminant C mixedor dissolved in the liquid portion L thereof. The fluid treatment system10 comprises a generally enclosed and substantially airtight container12 defining an interior volume 12 v. The container 12 may comprise abottom 12 b, side walls 12 s, and a top 12 t. The container 12 isdesigned to contain and hold gases and liquids. A preferred material forthe container is steel. More preferably, the container 12 is a pressurevessel suitable for pressures up to 15 psi and generally constructed of⅜^(th) thick corrugated carbon steel, coated for sour service.

The container 12 may conveniently be in the form of a 35 foot long, by 8foot wide, by 8 foot high generally rectangular tank, having an internalvolume 12 v capacity of at least 325 barrels and being suitable fortransportation by highway travel, such as by tractor semi-trailer, whilestaying within common weight and dimensions regulations. FIG. 2illustrates one embodiment of such a generally rectangular tank, havinga height H, a width W and a longitudinal axis LA that maybe heldsubstantially along the horizontal plane when the container 12 is inoperation or when it is transported. Other container dimensions, suchas: (i) a 53 foot long, by 8 foot wide, by 8 foot high generallyrectangular tank, having an internal volume 12 v capacity of at least600 barrels and (ii) a 50 foot long, by 8 foot wide, by 8 foot highgenerally rectangular tank, having an internal volume 12 v capacity ofat least 500 barrels, will also work.

The container 12 may also be substantially in the form of a cylinder,such as a fuel transport tank carried by a tractor semi-trailer. FIG. 7illustrates one embodiment of such a generally cylindrical tank, havinga height H and a longitudinal axis LA which maybe held substantiallyalong the horizontal plane when the container 12 is in operation and/orwhen it is transported. The container 12 of the embodiment of FIG. 7preferably has an interior volume 12 v of at least 200 barrels, a length(along the longitudinal axis LA) of at least 44 feet and a diameter ofat least 6 feet.

The container 12 has at least one inlet 12 i to receive the contaminatedfluid F and to subsequently direct said fluid F into the interior volume12 v (either directly or via additional conduits, such as a diverter50). The container also has at least one gas outlet 12 g to dischargeany gaseous contaminant C, that may escape from the contaminated fluid Fin gaseous form, out of the interior volume 12 v.

The container 12 further comprises at least one liquid outlet 121 todischarge any liquid L, separated from said contaminated fluid F, out ofthe interior volume 12 v. The container is sealed to maintain a sealbetween the interior volume 12 v and the outside environment, so as toprevent the escape and/or movement of any liquids and gasses out of theinterior volume 12 v, except as may be provided for via the inlet 12 i,the gas outlet 12 g or the liquid outlet 121.

Preferably the inlet 12 i is provided substantially at one end 13 of thecontainer 12, while the gas outlet 12 g and the liquid outlet 121 areprovided at a substantially opposing end 14. More preferably, if thecontainer is a generally rectangular tank having a longitudinal axis LA,the inlet 12 i is provided substantially at one end 13 of the container12 along the longitudinal axis LA, while the gas outlet 12 g and theliquid outlet 121 are provided at a substantially opposing end 14 alongthe longitudinal axis LA.

The gas outlet 12 g is preferably provided near the top 12 t, so as toallow easy exit (or drawing off) of any gaseous contaminant C, while theliquid outlet 121 is preferably provided near the bottom 12 b, so as toallow easy exit (or drawing off) of liquid L. The gas outlet 12 g may beprovided with a diverter 51 and opening 51 o, to allow it to befunctionally positioned within the container 12 and with opening 510near the top 12 t (see the embodiment of FIG. 7). Likewise, the liquidoutlet may be provided with a stinger 52 or the like to allow anoperator to draw off liquid L via the liquid outlet 121 at a level ofonly an inch or so above the bottom 12 b (see the embodiment of FIG. 2).

The contaminated fluid F may come from a contaminated fluid source 20such as a well, a storage tank or a separator, and a pump 20 p may beprovided to move contaminated fluid F from the source 20 into thecontainer 12 and provide sufficient line pressure of the fluid F duringoperations. During operations a suitable line pressure is 200 psi, and asuitable flow rate for the fluid F into the interior volume 12 v is upto 300 barrels per hour when the container's interior volume is at least600 barrels.

Those skilled in the art can appreciate that the particular elements inthe embodiments depicted in the figures are connected using typicalconnections known to those skilled in the art, such as the appropriatepipes, seals, caps, clamps, tubes, o-rings, valves, etc. (and asgenerally illustrated by the letter P). For example, a suitable pipe toprovide contaminated fluid F from the source 20 to the inlet 12 i is a 3or 4 inch diameter steel pipe.

The contaminated fluid F is expected to be primarily liquid L, such ascrude oil or water, with one or more gaseous contaminants C generallybeing dissolved or mixed therein. A common contaminant C that the system10 can treat is hydrogen sulfide (H2S). But the system 10 is alsosuitable to treat fluid F contaminated with volatile organic compounds(VOC) or other gaseous contaminants C that readily escape or break outof liquid in a gaseous form at common atmospheric conditions.

During operation of the system 10, contaminated fluid F enters theinterior volume 12 v under pressure and will then rapidly expand intothe greater volume provided for by the interior volume 12 v. This willcause a significant portion of the gaseous contaminants C to separate orbreak-out from the liquid portion L. Gravity will cause the liquidportion L will fall or settle on the bottom 12 b, while the gaseouscontaminants C remain in the upper portion of the container or headspaceHS, suitable then to exit out of the container 12 via the gas outlet 12g.

As more liquid L settles on the bottom 12 b, the liquid level LL willrise or increase in height within the interior volume 12, reducing thevolume of headspace HS. The liquid L may be drawn out from the container12 via the liquid outlet 121, such as by means of a suitable pump 25.Preferably, during operation, the liquid L is drawn out of the interiorvolume 12 (via liquid outlet 121) at such a rate (or at such batchintervals) so as to keep the liquid level LL below half the tank'sheight H; i.e. so as to keep the headspace HS to at least fifty percent(50%) of the interior volume 12 v. Liquid sensors may be provided toautomate or trigger a pump 25 to draw out liquid L when the liquid levelLL reaches a preset threshold along the height H of the container, e.g.at forty-five percent (45%) height, so as to ensure that the liquidlevel LL remains below half the tank's height.

Advantageously, by keeping the headspace HS to at least fifty percent ofthe interior volume 12 v, most or all of the remaining gaseouscontaminants C′ in the liquid L will very quickly separate therefrom(into the headspace HS), thereby significantly increasing the efficiencyof the system 10. In contrast, if the headspace HS was reduced to lessthan ten percent (10%) of the interior volume 12 v, the vapor-liquidphase equilibrium of a gaseous contaminant C (such as hydrogen sulfide)may cause a larger portion of that contaminant C to remain dissolved ormixed within the fluid F, and then also the liquid portion L, as thefluid F settles in the container 12.

Any liquid L draw out of the container 12 via the liquid outlet 121 maybe sampled at a sampling port S to determine what amount or percentageof gaseous contaminants C may still remain in the liquid portion L. Ifthe liquid portion has be substantially treated and cleaned of gaseouscontaminants C, it may be drawn off into a liquid storage or transportvessel 27. Alternatively, if the liquid portion still contains somecontaminants C, it may be drawn off and then reintroduced into thecontainer 12 via a recycling loop R that fluidly connects to the inlet12 i.

Any gaseous contaminants drawn off or exiting via the gas outlet 12 gmay be stored in suitable containers, flared off using a flare stack or,more preferably, treated using suitable gas scrubbers 29. For example, aSCRUBBER MAX™ HGR™ high gas rate scrubber made by Am-gas Services Inc.of Rockyview, Alberta, Canada is suited for controlling and removingtoxic gases in high flow, low pressure venting applications (with a flowrate of 140 cubic meters/minute) and would be a suitable scrubber 29when the contaminant C is hydrogen sulfide. Preferably, the gas outlet12 g is a six inch diameter outlet to facilitate easy connection to agas scrubber 29 via pipes P, to handle a high gas flow rate and to allowfor the carrier gas G to quickly purge the headspace HS of the container12 so as to allow a system 10 (with a 53 foot×8 foot×8 foot container 12having a 650 barrel internal volume 12 v) to efficiently treat typicaloil-field contaminated fluids F, such as sour oil with a hydrogensulfide concentration of up to 500,000 ppm, at a rate of 325 barrels perhour.

Advantageously, by causing the gaseous contaminant C to separate from(or leave) the liquid portion L, the system 10 avoid the need for achemical scavenger to be introduced into the liquid portion. Moreadvantageously, if the fluid F is crude oil, no chemical scavenger isintroduced into the liquid portion of the crude oil, thereby preventingany dithiazine buildup in downstream oil processing equipment, pipes andstorage tanks; as would be the case with prior-art chemical scavengertreatment systems and methods.

Preferably, when treating typical fluids contaminated with hydrogensulfide (H2S) the system 10 provides at least one (1) square foot, butmore preferably at least 1.4 square feet, of surface area per barrel ofcontaminated fluid F being treated. The inventor has found that thisamount or ratio of surface area per barrel of fluid encourages quick andalmost instantaneous breakout or escape of any gaseous contaminants C(like hydrogen sulfide) from the liquid portion L. Thus a 53 foot longby 8 foot wide container 12 will provide a surface area of 424 squarefeet and should therefore be suitable to treat approximately 302 barrelsof hydrogen sulfide contaminated fluid per hour. Advantageously, ahorizontally oriented container 12, with its longitudinal axis LAsubstantially along the horizontal plane, will provide a much greatersurface area to the liquid L on the bottom 12 b per volume of liquid Lthan an upright/vertical container of the similar dimensions but havingits longitudinal axis along the vertical plane. In that case, thesurface area of such an upright/vertical container would only be 64square feet (8 feet×8 feet) and, keeping the 1.4 square feet ratio (perbarrel of fluid), would then really only be suitable to treat 46 barrelsof H2S contaminated fluid F per hour.

Preferably, the system 10 further comprises a source 30 of carrier gas Gwhich is introduced or mixed into the contaminated fluid F prior to thecontaminated fluid F entering the interior volume 12 v. The carrier gasG may be air or an inert gas, such as nitrogen gas (N2). The carrier gasG can be selected by those skilled in the art based on the carrier gas'sability to accept (i.e. “carry”) the contaminant C away from the fluidF, while also being safe to handle. For example, air is generallysuitable to accept hydrogen sulfide (H2S) contaminants from contaminatedwater. Air, however, may not be desirable as a carrier gas G when thecontaminated fluid F is crude oil, due to the potential combustible andexplosive reaction of the oxygen in the air with the hydrocarbons in theoil. As such, in the case where the contaminated fluid F is primarilycrude oil, the carrier gas is preferably an inert gas such as nitrogengas (N2) to decrease the probability of combustion. Advantageously, thecarrier gas G also functions to purge or clear out the headspace HSvolume on a continuous basis during operation of the system 10, therebymaintaining a favourable vapor-liquid phase equilibrium for any gaseouscontaminant C (such as hydrogen sulfide), so that most or all of theremaining gaseous contaminants C′ in the liquid L are caused to quicklyseparate therefrom (into the headspace HS and then out the gas outlet 12g). More advantageously, the carrier gas G creates additional turbulenceto the contaminated fluid F when it enters the interior volume 12 v(e.g. near the top 12 t), thereby significantly increasing theefficiency of the initial break-out of gaseous contaminant C into theheadspace HS and adding to the overall efficiency of the system 10.

Preferably, the carrier gas G is mixed into the contaminated fluid Funder pressure, prior to the mixture of contaminated fluid and carriergas F,G being released into the interior volume 12 v. For example, thecarrier gas G may already be held within a source 30 under sufficientpressure; e.g. at a pressure of at least 100 psi. Alternatively, thecarrier gas G may be drawn from a source using a pump to achieve thedesired pressure, prior to mixing with the contaminated fluid.

When the fluid F enters the interior volume 12 v at a rate of up to 300barrels per hour, the carrier gas G is preferably mixed into thecontaminated fluid at a rate of 75 to 125 standard cubic feet per minute(scfm) if the carrier gas G is nitrogen, or at a rate of 150 to 350 scfmif the carrier gas is air.

The carrier gas G may be mixed into the contaminated fluid F using amixer 40 such as mixing chamber 40 c or a venturi 40 v. The mixer 40 maybe provided externally to the container 12, as in the embodiment of FIG.1; or the mixer 40 may be provided inside the container 12, as in theembodiment of FIGS. 2 to 6.

The mixture of contaminated fluid and carrier gas mixture F,G ispreferably released into the interior volume 12 v near the top 12 t ofthe container 12. This may be accomplished by having the inlet 12 ilocated on the top 12 t, as in the embodiment of FIG. 1. Or this may beaccomplished by providing one or more rising diverters 50 to divertraise the contaminated fluid and carrier gas mixture F,G from an inlet12 i that may be near the bottom of the container 12 up to the top 12 t,as in the embodiments of FIGS. 2 to 6. The diverters 50 receive themixture F,G from the inlet 12 v and have an outlet 50 o that exits inthe interior volume 12 v near the top 12 t. Advantageously, by allowingthe inlet 12 i to remain near the bottom of the container 12, a sourceof contaminated fluid 20 may be easily connected to the container 12(via pipes P) by workers and operators on the ground. Rather than havingto connect directly to the top 12 t of an eight foot tall container 12.

More advantageously, by providing a carrier gas G, by premixing thatcarrier gas G into the fluid F prior to release into the interior volumeand by releasing this mixture near the top 12 t of container, theinventor has found that the gaseous contaminant C is quickly and veryefficiently separated from the fluid F and into the headspace HS, withvery little (if any) remaining in the liquid portion L; i.e. thevapor-liquid phase equilibrium of a gaseous contaminant C (such ashydrogen sulfide) is shifted in favour of the gaseous contaminantquickly and efficiently breaking-out of the liquid portion L. Moreadvantageously, by providing a substantially rectangular container 12with a height H of eight (8) feet, the container 12 will fit underneathbridges and meet most or all local vehicle and traffic regulations whentransported on a semi-truck from one remote location to another. Evenmore advantageously, by providing a substantially rectangular container12 with the inlet 12 i (or the diverter 50 with opening 50 o) atsubstantially one end 13 and with the gas outlet 12 g at a substantiallyopposing end 14 along that length, a large volume of effective headspaceHS is provided to allow gaseous contaminant C to escape from the liquidportion L before exiting out the gas outlet 12 g; i.e. the vapor-liquidphase equilibrium of a gaseous contaminant C (such as hydrogen sulfide)is again shifted in favour of the gaseous contaminant quickly andefficiently breaking-out of the liquid portion L. Additionally, byhaving the inlet 12 i (or the diverter 50 with opening 50 o) atsubstantially one end 13 and with the gas outlet 12 g at a substantiallyopposing end 14, any liquid or mist carry-over out the outlet isminimized, if not outright eliminated.

In any event, during operation, the liquid level LL is to be kept belowboth the inlet 12 i (or the diverter's opening 50 o) and the gas outlet12 o (or the diverter's opening 51 o), so as to provide at least somecontinuous headspace HS within the interior volume 12 v to allow gaseouscontaminants C,C′ and any carrier gas G to travel from the inlet 12 i(or from the diverter's opening 50 o), or from the liquid portion L, tothe gas outlet 12 o (or the diverter's opening 51 o). Preferably, duringoperations, the liquid LL is kept at least one inch below both the inlet12 i (or the diverter's opening 50 o) and at least one inch below thegas outlet 12 o (or the diverter's opening 51 o).

As noted above, preferably, the liquid level LL is kept below half thetank's height H; i.e. so as to keep the headspace HS to at least fiftypercent (50%) of the interior volume 12 v. However, the inventor hasnoted that keeping the headspace to at least 10% of the interior volume12 v will also work, with the greatest efficiencies begin found when theheadspace HS is kept to at least fifteen percent (15%).

Finally, it is known that sulfur and sulfide oxidizing micro-organismsinclude both bacteria (e.g. Thiobacillus species) and Archaea (e.g.Sulfolobus species). Such oxidizers oxidize H2S (sulfide) or S(elemental sulfur) as a source of energy. Similarly, the purple andgreen sulfur bacteria oxidize H2S or S as an electron donor forphotosynthesis. With respect to the system 10, the inventor hasdiscovered that, when the contaminated fluid F being treated is watercontaminated with hydrogen sulfide, the system 10 quickly andefficiently removes not only the hydrogen sulfide from the liquidportion L, but also any sulfur and sulfide oxidizing micro-organismsfrom the liquid portion L—since their energy source (H2S) is quicklyremoved. The inventor has observed cellular materials precipitating outof the liquid portion L and settling on the bottom 12 b, as such sulfurand sulfide oxidizing micro-organisms die from lack of energy.Advantageously, the system 10 can now also be used to minimize (oreliminate) subsequent or down-stream waste water treatments, such asadding oxidizing chemicals, that would typically be used to kill anysuch micro-organisms in the liquid portion L.

Those of ordinary skill in the art will appreciate that variousmodifications to the invention as described herein will be possiblewithout falling outside the scope of the invention. In the claims, theword “comprising” is used in its inclusive sense and does not excludeother elements being present. The indefinite article “a” before a claimfeature does not exclude more than one of the features being present.

The embodiments of the invention in which an exclusive property orprivilege is being claimed are defined as follows:
 1. A fluid treatmentsystem for treating a contaminated fluid having a gaseous contaminantmixed or dissolved in the liquid portion thereof, the system comprising:a generally enclosed and substantially airtight container defining aninterior volume; the container further comprising: at least one inlet toreceive the contaminated fluid; at least one gas outlet to discharge anygaseous contaminant; at least one liquid outlet to discharge any liquidthat may be separated from said contaminated fluid; wherein, duringoperations, the container is sealed to maintain a seal between theinterior volume and any outside environment, so as to prevent the escapeand/or movement of any liquids and gasses out of the interior volume,except as may be provided for via the inlet, the gas outlet or theliquid outlet; and wherein, during operations, a continuous headspace ismaintained between the at least one inlet and the at least one gasoutlet; and the system further comprising: a gas scrubber to receive andremove any gaseous contaminants exiting the said at least one gasoutlet.
 2. The fluid treatment system of claim 1 wherein the containerfurther comprises a longitudinal axis and wherein, during operations,the container is positioned so that the longitudinal axis is heldsubstantially along a horizontal plane; and wherein the inlet isprovided substantially at one end of the container's longitudinal axis,while the at least one gas outlet is provided at a substantiallyopposing end of the container's longitudinal axis.
 3. The fluidtreatment system of claim 1 wherein the interior volume provides atleast 1 square foot of surface area per barrel of contaminated fluidbeing treated.
 4. The fluid treatment system of claim 1 wherein theinterior volume provides a square surface area of at least 424 squarefeet.
 5. The fluid treatment system of claim 1 further comprising arecycling loop fluidly connecting the at least one liquid outlet withthe at least one inlet.
 6. The fluid treatment system of claim 1 furthercomprising a source of carrier gas premixed into the contaminated fluid.7. The fluid treatment system of claim 6 wherein the carrier gas isselected from one of: air or nitrogen.
 8. The fluid treatment system ofclaim 6 further comprising a mixer, to mix the carrier gas with thecontaminated fluid.
 9. The fluid treatment system of claim 8 wherein themixer is selected from one of: a mixing chamber or a venture.
 10. Thefluid treatment system of claim 1 wherein the container furthercomprises a longitudinal axis and wherein, during operations, thecontainer is positioned so that the longitudinal axis is heldsubstantially along a horizontal plane.
 11. The fluid treatment systemof claim 1, wherein the gas scrubber is a high gas rate scrubber able toremove toxic gases at a flow rate of at least 140 cubic meters/minute.12. The fluid treatment system of claim 17, wherein the gas outlet has adiameter of at least six inches; and wherein the gas scrubber isconnected to the gas outlet via at least one pipe.